What the frack?

In response to public concern over expanding shale exploration and “fracking” oil-extraction methods, the U.S. Interior Department plans to begin forcing oil companies to document the chemicals they use in the drilling process.

The government hopes to issue new rules for fracking—or hydraulic fracturing—within the next few months, according to media sources. Fracking involves the high-pressure injection of a mixture of water, sand and numerous chemicals into shale formations to allow oil and gas to escape. Concern centers around possible groundwater contamination and air pollution associated with the process.

The new regulations come on the heels of news that fracking operations conducted by U.K. company Cuadrilla Resources in northwest England likely were the cause of two small earthquakes in April and May. A team of independent seismic experts hired by Cuadrilla concluded it was “highly probable” fracking resulted in the magnitude 2.3 and 1.5 quakes. The company has since halted operations at the site.